hey- I'm one of those "loozers"...albeit mine is actually charging. I almost took a picture this morning because I thought it was cool how many Tesla's were parked in a row. I agree with a 110 plug, I did feel bad taking up a space knowing that in 5 hours my car will be fully charged but I'm not getting back until tomorrow. But Dulles made that decision so why not use them.
For what it's worth, there are many reasons why someone would park and not charge. I can see how folks would feel more comfortable parking their car with other Tesla's, knowing some ICE jerk isn't going to slam their car door and dent their S (strength in numbers if you will). In fact, one person had a temporary tag brand new titanium S parked there. Maybe they couldn't figure out the charge process (you do have to register) and/or maybe they didn't know the etiquette being a new owner. All I'm trying to say is; shaming isn't a friendly way to help people feel like part of the community.